Many girls and young women in Bangladesh choose to keep their experiences of sexual harassment or abuse secret for fear of being shamed by society or their families. What made Nusrat Jahan different is that she didn't just speak out - she went to the police with the help of her family on the day the alleged abuse happened.
At the local police station she gave a statement. She should have been provided with a safe environment to recall her traumatic experiences. Instead she was filmed by the officer in charge on his phone as she described the ordeal.
In the video Nusrat is visibly distressed and tries to hide her face with her hands. The policeman is heard calling the complaint "no big deal" and telling her to move her hands from her face. The video was later leaked to local media.
On 27 March, after she went to the police, they arrested the headmaster. Things then got worse for Nusrat. A group of people gathered in the streets demanding his release. The protest had been arranged by two male students and local politicians were allegedly in attendance. People began to blame Nusrat. Her family say they started to worry about her safety.
Nevertheless, on 6 April, 11 days after the alleged sexual assault, Nusrat went to her school to sit her final exams.
According to a statement given by Nusrat, a fellow female student took her to the roof of the school, saying one of her friends was being beaten up. When Nusrat reached the rooftop four or five people, wearing burqas, surrounded her and allegedly pressured her to withdraw the case against the headmaster. When she refused, they set her on fire.
Police Bureau of Investigation chief Banaj Kumar Majumder said the killers wanted "to make it look like a suicide". Their plan failed when Nusrat was rescued after they fled the scene. She was able to give a statement before she died.
"One of the killers was holding her head down with his hands, so kerosene wasn't poured there and that's why her head wasn't burned," Mr Majumder told BBC Bengali.
But when Nusrat was taken to a local hospital, doctors found burns covering 80% of her body. Unable to treat the burns, they sent her to Dhaka Medical College Hospital.
In the ambulance, fearing she might not survive, she recorded a statement on her brother's mobile phone.
"The teacher touched me, I will fight this crime till my last breath," you can hear her say.
She also identified some of her attackers as students at the madrassa.
